How fast do you need the money?
You could follow Minecraft's example and charge a small amount of money for the alpha version. When it goes in beta, you'll have to pay more. And even more when it comes out of beta.
I'm not sure how many developers are interested in C2 at the moment. (Minecraft is a game and got very popular, very quickly). This might not be the case with C2..) If there are thousands of people already interested in C2, this method might get you started..
p.s. I would also pay up to 80 dollars for a pro version. I even wouldn't mind a % of the profit to go to Scirra either..